1. Field of the Invention
The present invention relates to a relay and method for protecting a transformer, and more particularly, to a relay and method for protecting a transformer capable of preventing a malfunction occurring when a transformation ratio of a transformer has been incorrectly set, and a transformer protecting system having the same.
2. Background of the Invention
The conventional transformer protecting relay is configured to allow a user to set a transformation ratio of a transformer. That is, a user sets a voltage ratio of the transformer, and a current ratio between a primary current transformer and a secondary current transformer.
This is implemented so as to make different electricity amounts input to the primary current transformer and the secondary current transformer equal. Based on the electricity amount of the same level, the transformer protecting relay determines whether an accident has occurred or not.
However, the conventional transformer protecting relay may have the following problem. When the voltage ratio and the current ratio (transformation ratio) have been incorrectly set due to a user's mistake, etc., the relay may malfunction.